Temporal response properties of koniocellular (blue-on and blue-off) cells in marmoset lateral geniculate nucleus

Abstract

Visual perception requires integrating signals arriving at different times from parallel visual streams. For example, signals carried on the phasic-magnocellular (MC) pathway reach the cerebral cortex pathways some tens of milliseconds before signals traveling on the tonic-parvocellular (PC) pathway. Visual latencies of cells in the koniocellular (KC) pathway have not been specifically studied in simian primates. Here we compared MC and PC cells to "blue-on" (BON) and "blue-off" (BOF) KC cells; these cells carry visual signals originating in short-wavelength-sensitive (S) cones. We made extracellular recordings in the lateral geniculate nucleus (LGN) of anesthetized marmosets. We found that BON visual latencies are 10-20 ms longer than those of PC or MC cells. A small number of recorded BOF cells (n = 7) had latencies 10-20 ms longer than those of BON cells. Within all cell groups, latencies of foveal receptive fields (<10° eccentricity) were longer (by 3-8 ms) than latencies of peripheral receptive fields (>10°). Latencies of yellow-off inputs to BON cells lagged the blue-on inputs by up to 30 ms, but no differences in visual latency were seen on comparing marmosets expressing dichromatic ("red-green color-blind") or trichromatic color vision phenotype. We conclude that S-cone signals leaving the LGN on KC pathways are delayed with respect to signals traveling on PC and MC pathways. Cortical circuits serving color vision must therefore integrate across delays in (red-green) chromatic signals carried by PC cells and (blue-yellow) signals carried by KC cells.

Visual response properties of neurons in the superficial layers of the superior colliculus of awake mouse

“…We included units where two consecutive bins in the PSTH exceeded the spontaneous rate by at least 2.5 SD of that rate and performed a linear regression from the first of those bins to the bin that contained the response peak. Latency was defined as the intersection of the regression line and the spontaneous rate (Pietersen et al 2014). All fits were inspected manually: where the automated procedure clearly failed, a line was fit to the rising phase of the PSTH using manually selected data points and the latency obtained as above.…”

“…Latency was defined as the intersection of the regression line and the spontaneous rate (Pietersen et al . ). All fits were inspected manually: where the automated procedure clearly failed, a line was fit to the rising phase of the PSTH using manually selected data points and the latency obtained as above.…”

Temporal properties of colour opponent receptive fields in the cat lateral geniculate nucleus

“…At first sight the data in Fig. A and C seem to contradict the literature on identified X‐ and Y‐cells (Frishman et al ., ; Weng et al ., ) or primate parvocellular and magnocellular neurones (Pietersen et al ., ). There are, however, indications that this relationship is not ubiquitous.…”

“…Pietersen et al . () found that the visual latencies of blue‐ON cells in marmoset LGN are 10–20 ms longer than those of parvocellular or magnocellular cells, however, another study from macaques (Tailby et al ., ) reported only trivial differences between blue‐ON and parvocellular cells. Our results are broadly consistent with these results: we found visual latencies of blue‐ON cells from the cat LGN lag behind those of achromatic cells by around 7–13 ms and the difference is on the margin of statistical significance (Figs.…”

“…The low frequency preference and long visual latency of blue-ON neurones of the cat is not unexpected. There is evidence that the pathways conveying signals for S-('blue')-cone based vision in primates are in some way slower or more sluggish than the pathways carrying L-('red') and M-('green') cone signals alone (Stromeyer et al, 1991;Cottaris & De Valois, 1998;McKeefry et al, 2003;Smithson & Mollon, 2004;Lee et al, 2009;Pietersen et al, 2014). Blue-ON cells of the retina and LGN are part of the W-cell system in cats (Daw & Pearlman, 1970;Cleland & Levick, 1974;Cleland et al, 1976;Wilson et al, 1976;Buz as et al, 2013) and they are part of the koniocellular system in primates White et al, 1998;Roy et al, 2009).…”